Primer for consumable round



June 8, 1965 J, QUINLAN ETAL 3,187,671

PRIMER FOR CONSUMABLE ROUND Filed Aug. 1, 1962 JNVENTORS, JOSEPH QUINLANJOHN SCANLON EARL F VAN ARTSDALEN ,3.) flotho i a United States atent3,187,671 PRINIER FOR CONSUMABLE ROUND Joseph Quinlan, Philadelphia,Pa., John J. Scanlon, Levittown, N.J., and Earl F. Van Artsdalen,Philadelphia, Pa., assignors to the United States of America asrepresented by the Secretary of the Army Filed Aug. 1, 1962, Ser. No.214,152 4 Claims. (Cl. 10243) (Granted under Title 35, US. Code (1952),sec. 266) The invention described herein may be manufactured and used byor for the Government for governmental purposes without the payment tous of any royalty thereon.

This invention relates to a light Weight small arms round of ammunitionand has for an object to produce a so called consumable round of thistype which is ballistically similar to the standardized metal case roundand which eliminates a disadvantage that has been discovered for suchprevious round, namely a too prevalent number of misfires. It has beendiscovered that a substantial portion of,such misfires has been due tothe consumable round being too yieldable for the firing pin to functionsatisfactorily when there is no base flange on the cartridge case asoccurs with the usual round having a metal case needing extraction of afired case from a gun.

Investigation has shown the solution of the problem does not reside inthe provision of a stiff metal base and flange enabling extraction ofthe base after firing because the base is the heavy portion of the caseand efforts to obtain a lighter weight case have been reluctant tocompromise with retention of a weighty portion of the standard case.

According to this invention it has been found that a change in theprimer is sufficient to enable a usual consumable round to be free ofthis objectional percentage of misfires. The term primer is usedthroughout the specification in the same guise as is commonly used inthe ordnance art, that is, explosives employed to supply the initialimpulses in explosive trains, further characterized by those sensitiveexplosives or mixtures used to initiate the explosion of otherexplosives, generally less sensitive. This is the definition adopted inHayes, Elements of Ordnance, 1938. The usual primer cup and anvil hasbeen changed to make the primer function satisfactorily even though itbe as yieldable as happens in the consumable round. More specificallythe usual primer mix is used but without the anvil. Instead a moresensitive explosive is used and is fired by impingement of the firingpin. This more sensitive explosive fires the usual primer material whichthen functions as a booseter to fire the propellant. This invention isbelieved to reside in the discovery of the cause of the misfiresreferred to, after which the use of a sensitive explosive, and a boostercharge may be within the skill of the art once the nature of thedifficulty has been found.

Still more specifically an explosive cap of the type used in toy pistolshas been placed in rear of the primer mix for the purpose stated andboth the primer and the rear topping charge may be wrapped together orseparately in a thin-paper envelope or an adhesive may be used for thetopping charge. Preferably an arrangement like that illustrated has beenfound most suitable to fill the old need for a consumable case afterGerman and Belgian efforts to devise such a case had not provensatisfactory.

Referring to the drawings:

FIG. 1 is a longitudinal section through one embodiment of thisinvention shown magnified for a 30 caliber consumable round having aconsumable case rear end portion.

FIG. 2 is a view similar to FIG. 1 in which no consumable plastic caseis used (caseless round).

FIG. 3 shows this invention embodied in a metal primer case for use in ametal cartridge case.

As shown in FIG.1 propellant 10 for a projectile or blank round is shownwithin a consumable case 11 of some known type having in the rear ofcase 11 a primer mix 12 of any well known sort having in rear thereof atopping charge 13 of a material that is more sensitive to explosion thanis the primer mix. This charge 13 is preferably made of about thefollowing constituents by weight: potassium chlorate 44%, antimonysulfide 49%, red phosphorus 5.5%, magnesium carbonate 0.5 and a binderof the type used for primer materials such as a gum arabic or gumtragacanth 1%. The red phosphorus is the fuel which is ignited first byheat or friction or both and may be varied from about 3% to 6%. Thepotassium chlorate is known to be the oxidizer, the antimony sulfide isfor the creation of friction and heat. In event of the formation ofphosphoric acid the magnesium carbonate is a neutralizer for the acid.The binder may suflice to hold the topping charge in place without theneed for the usual thin paper envelope in which this general type chargehas been used when sold for toy pistols. In FIG. 2 is shown the sameinvention as illustrated in FIG. '1 except that there is no consumablecase 11 rather FIG. 2 represents a caseless round and the primer andtopping charges 12 and 13 are held together as a unit by either asuitable binder or an envelopeof thin paper. The propellant is likewiseheld together by a thin consumable envelope of paper, or silk, or by anappropriate binder, of which a number are known.

In both FIGS. 1 and 2 the firing pin or hammer is preferably providedwith a conical or tapered point capable of entering the topping chargecreating tenough heat by friction to ignite the phosphorus and the restof the topping charge, then the primer mix, and next the propellant.

In FIG. 3 the metal primer case 14 contains the primer mix 12 andtopping charge 13 and is for use where a metal cartridge case is used.The firing pin enters the top of the charge 13 in FIGS. 1 and 2 but inFIG. 3 it must dent in the closed end of the metal case 14 and ing-itethe sensitive phosphorus and other ingredients of the charge 13. Theprimer flame issues through hole 15 in the metal case for ignitingpropellant. In FIG. 2 there is no hole corresponding to hole 15 in FIG.3 because the primer flame issues in any lateral and downward directionsto fire the propellant 10. In FIG. 1 a hole 15 is shown but since thewalls 11 of that hole are consumable the primer flame will issue bothlaterally and downward although slightly more heavily through hole 15 inthis FIG. 1.

An advantage of this improvement in FIGS. 1 and 2 is the reduction inmisfires with a caseless or consumable case where no base flange ispresent for extraction of a fired case when there is no case needing tobe extracted. An advantage of this invention in each of the threeembodiments illustrated is the elimination of the hazard of assembling aprimer containing the usual anvil when dependence is placed on frictionand the heat resulting therefrom instead of depending upon crystalshear. The assembly of primer cups containing an anvil has proven fobhazardous. In all figures a bolt or breechclosure prevents any rearwardfire of the round.

The term consumable round as applied to a cartridge includes one whichhas no case, or better known as caseless, and one which has a consumablecasing.

We claim:

1. In a round having a consumable cartridge case the combination of apropellant, a primer in the rear of said propellant, said primercomprising a body of primer mix contiguous said propellant in a toppingcharge defined by a body of explosive material fixed on the rear of saidprimer mix body, said topping charge being more sensitive to ignition byimpact than is said primer mix whereby upon impact by a firing pin orthe like said topping charge fires said primer mix and said primer mixin turn fires said propellant, and said topping charge including thefollowing ingredients in percentage by Weight:

Potassium chlorate 44 Antimony sulfide 49 Red phosphorus 5.5 Gum' arabicor gum tragacanth' 1.0 Magnesium carbonate 0.5

2. In a caseless round the combination of a propellant, a primer in therear of said propellant, said primer comprising a body of primer mixcontiguous said propellant and a topping charge defined by a body ofexplosive material fixed on the rear of said primer mix body, saidtopping charge/being more sensitive to ignition by impact than is saidprimer mix whereby upon impact by a firing pin or the like said'toppingcharge fires said primer mix 20 and said primer mix in turn fires saidpropellant, and said topping charge including the following ingredientsin percentage by weight:

Potassium chlorate 44 Antimony sulfide 49 Red phosphorus 5.5 Gum arabicor gum tragacanth 1.0 Magnesium carbonate 0.5

3. In a round the combination of a propellant, a primer in the rear ofsaid propellant, a consumable enclosure for said primer, said enclosuredefining a forward end with a generally axial perforation therethroughwhich forward end is contiguous the propellant, said primer comprising ra body of primer mix in the forward end of said enclosure Potassiumchlorate s44 Antimony sulfide 49 Red, phosphorus 5.5 Gum arabic or gumtragacanth 1.0 Magnesium carbonate 0.5

References Cited by the Examiner UNITED STATES PATENTS 53,168 3/66Moffatt 102 110,266, 12 Moffatt 102-45 2,194,480 3/ 40 Pritham 149-292,872,870 2/59 Gey 102-39 X 2,982,211 5/61 B681 6t 8.1 102-43 FOREIGNPATENTS 455,382 1/28 Germany.

SAMUEL FEINBERG, Primary Examiner. SAMUEL BOYD. Examiner.

1. IN A ROUND HAVING A CONSUMABLE CARTRIDGE CASE THE COMBINATION OF APROPELLANT, A PRIMER IN THE REAR OF SAID PROPELLANT, SAID PRIMERCOMPRISING A BODY OF PRIMER MIX CONTIGUOUS SAID PROPELLANT IN A TOPPINGCHARGE DEFINED BY A BODY OF EXPLOSIVE MATERIAL FIXED ON THE REAR OF SAIDPRIMER MIX BODY, SAID TOPPING CHARGE BEING MORE SENSITIVE TO IGNITION BYIMPACT THAN IS SAID PRIMER MIX WHEREBY UPON IMPACT BY A FIRING PIN ORTHE LIKE SAID TOPPING CHARGE FIRES SAID PRIMER MIX AND SAID PRIMER MIXIN TURN FIRES SAID PROPELLANT, AND SAID TOPPING CHARGE INCLUDING THEFOLLOWING INGREDIENTS IN PERCENTAGE BY WEIGHT: